Aircraft wing flap and aileron combination having boundary layer control



AIRCRAFT WING FLAP AND AILERON COMBINATION HAVING BOUNDARY LAYER CONTROLFiled May 13, 1943 July 12, 1949. E. A. STALKER 2,476,001

/NVE/\/TOR Patented July 12 1949 AIRCRAFT WING FLAP AND AILERQN COM-BINATION CONTROL HAVING BOUNDARY LAYER Edward A. Stalker, Bay City,Mich.

Application May 13, 1943, Serial No. 486,790

Claims. I

My invention relates to wings, and particularly to means for obtaininglateral control with highly cambered wings. When a wing is highlycambered so that it can deflect the relative wind through an angle of 90degrees substantially no further lift is available from furthercambering the wing (as by moving the aileron) Hence rotation of theaileron through a still larger angle is not an effective andsatisfactory way in which to obtain lateral control under suchconditions. It is possible however to secure a lift force by emitting ajet of fluid with a substantially downward direction. It is alsopossible to control the jet in coordination with the aileron so thatthere is a continuous functioning of lateral control as the airplanepasses from high to low speed or vice versa.

It is therefore the principal object of the invention to provide forobtaining rolling moments from a wing in a high lift attitude where therelative wind is being deflected through a relatively large angle.

It is a further object to accomplish this control through the use of ajet discharge under properly controlled conditions.

It is a still further object to provide an aileron mechanism to controlthe jet mass.

I accomplish the above objects by the means illustrated in theaccompanying drawings in which- Fig. 1 is a top plan view of the wing;

Fig. 2 is a section along the line 2-2 of Fig. 1;

Fig. 3 is the same section as Fig. 2 with the flaps down;

Fig. 4 is a fragmentary detail of the flap mechanism; and

Fig. 5 is a bottom fragmentary view of the flap mechanism.

Referring to the drawing which discloses a preferred embodiment of myinvention, the wing is shown generally at I, it being understood thatthe construction of the opposite wing is similar. Ihe wing is composedof the main body la and the control flaps 2 and 3, arranged in tandem.The flaps are pivotally connected to each other providing for adjustmentthereof from the raised high speed position shown in Fig. 2 to thelowered high lift position shown in Fig. 3. As shown flaps are formedwith generously curved upper surfaces of longer radius of curvature thanthe thickness of the adjacent portion of the wing, so that in the highlift position a smooth upper curved surface will be obtained, giving awing with a highly cambered airfoil section,

outwardly of the respective flaps 3 on opposite wings are located theailerons 4., each aileron being arranged in tandem with itscorresponding flap element 2. The ailerons are formed similarly to theflaps, but are arranged through the usual controls to be actuated inopposite directions on the opposite wing-s. while flaps 2 and 3 arearranged to be operated in the same direction.

Flap 2 has the slot 5 formed adjacent the forward or nose portionthereof while flap 3 and aileron 4 each have a slot 6 located adjacentthe nose thereof and a second slot 1 located adjacent the trailing endthereof, Each of such slots extends over the major portion of the uppersurface of the wing span and preferably over substantially the entireextent thereof as shown in Fig, 1.

A horizontal fixed wall Ill is provided in the interior of the wingforming an upper passage through which air may flow. A power drivenblower 8 is suitably lQca-ted With. its intake in communication with theupper passage above wall l0, and provides for inducting air through eachof slots 5, 6 and 1, thereby providing for energizing the boundary layeron the upper wing surface over the area in advance of the respectiveslots. The slots 5 and 6 may if desired be so located that in the raisedposition of the flaps, the effectiveness thereof is reduced, oreliminated by being entirely enclosed within the trailing ends of thewing portions immediately in advance thereof; or these slots as Well asslot 1 may remain effective in all relative positions of the wing andflaps.

To maintain the passage above wall In during the movement and in thedeflected position of the flaps, a flexible wall Illa is providedsubstantially coextensive with the flap 2, and is secured at its forwardand rearward edges respectively with the corresponding non-flexiblewallslfi of the wing main body, and the rearmost flap portion. In thisWay the flaps may be moved relative to each other and to the main bodywhile providing a Continuous upper passage for the flow of the inductedair. A rod Illb supported from the lower wall of flap 2 engages theunder side of flexible wall Inc, and extends spanwise substantiallycentrally thereof to provide support therefor.

The air discharged from the blower is directed either directly orindirectly to a passage 9 on the leading edge of the wing defined bywall 9a. This passage is defined over the inner portion of the wing by awall 9a. which is coextensive with the vertical extent of the passage,thereby eifectively segregating the discharge passage from the suctionpassage through which the air is drawn into the blower. At the outerportion of the wing, i. e. that portion having the aileron 4 andcomprising in the form shown approximately the outer third of the wing,wall 9a extends downward only to laterally extending wall 10, forming acontinuation of the discharge passage 9 in the lower portion of thewing. A chordwise wall 91) extending from wall Ill downward to the lowerside of this continuation of the passage 9 encloses such passage andseparates the same from the path taken by the inducted air. In thisarea, the flap 2 on its lower surface is formed with a hinged auxiliaryflap l3 which extends rearwardly into overlapping relation with thelower surface of aileron 4. The aileron carries a cam plate H on itslower surface having grooves or slots l5 therein of predeterminedconfiguration. Auxiliary flap l3 carries pin M which have slidingengagement in slots IE to thereby control the angular relation betweenthe flap and the lower surface of the flap, providing a greater orlesser degree of opening ll through which the flow of air from lowerpassage 9 is discharged.

When the aileron is moved down by the pilot, the slot II is opened. Thecam slot I5 is given such a shape that, as the flaps are lowered, thewidth of slot II is increased slowly at first and then more rapidly asthe aileron approaches its extreme down position, the maximum change inthe opening occurring with the flaps in the fully lowered position.Hence with the flaps 2, 3 and 4 depressed, a small additionaldisplacement of the aileron gives a relatively large change in the sizeof the slot II. The greater mass of air then discharged gives a highrolling force which is effective in a direction favorable to the controldeveloped by the aileron itself.

All the flaps including the aileron are depressed to the high liftposition shown in Fig. 3 and the aileron is moved either way from thisinitially depressed position to give lateral control. A movement opensthe slot ll quickly and an up movement reduces the slot width. Thus evenwith the flaps fully depressed and with the wing having such high camberas to deflect the relative wind through an angle of substantially 90, alift force is developed and readily controlled to provide the desiredlateral control. The force of the jet discharge from slot II is undercontinuous control through the positioning of the ailerons, and acontrol force is thus developed by reason of the downward direction ofthe discharge which gives a rolling moment in the proper sensecoordinated with the positions of the respective ailerons.

It will now be clear that I have described an effective means ofobtaining lateral control for a wing operating near its maximum liftcoefficient, this means comprising a slot in the lower surface and meansto govern the quantity of air to be discharged from the slot. Thedischarged air passes from the blower along a passage forward of one ofthe spars and rearward under the spar to the slot in the lower surface.

While the forms of apparatus herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

1. In combination in an aircraft, a wing main body, an aileron and alift flap, means to support said body, flap and aileron in variablerelation to form a wing, means to depress said flap and aileron throughlarge angles to provide highly cambered airfoil sections, means defininga discharge slot in the wing lower surface, a blower in communicationwith said discharge slot to discharge a flow outwardly therethrough, thewalls of said slot being formed to direct a slot discharge flow of airdownward substantially normal to the said body in the depressed positionof said aileron, and means operable coincidentally with the downwarddisplacement of said aileron to increase the mass of air discharged fromsaid discharge slot to produce an increase in rolling force.

2. In combination in an aircraft, a wing main body, an aileron and alift flap, means to support said body, flap and aileron in variablerelation to form a wing, means to depress said flap and aileron throughlarge angles to provide highly cambered airfoil sections, a lowersurface flap spaced from said aileron and forming therebetween adischarge slot, a blower having its discharge in communication with saiddischarge slot to cause an outward flow therethrough, means foradjustably supporting said lower surface flap at one chordwise end onthe wing portion ahead of the aileron, and means supporting the otherend of said lower surface flap from said aileron providing for controlof said discharge slot in accordance with the position of said aileron.

3. In combination in an aircraft, a wing main body, an aileron and alift flap, means to support said body, flap and aileron in variablerelation to form a Wing, means to depress said flap and aileron throughlarge angles to provide highly cambered airfoil sections, a lowersurface flap spaced from said aileron and forming therebetween adischarge slot, a blower having its discharge in communication with saiddischarge slot to cause an outward flow therethrough, means foradjustably supporting said lower surface flap at one chordwise end onthe wing portion ahead of the aileron, means supporting the other end ofsaid lower surface fiap from said aileron providing for control of saiddischarge slot in accordance with the position of said aileron, andmeans providing for enlarging said discharge slot at an increasing rateas the aileron is moved toward its depressed position.

4. In combination in an aircraft, a wing main body, an aileron and alift flap, means to support u said body, flap and aileron in variablerelation to form a wing on each side of the aircraft, means to depressthe said flaps of opposite wings coincidentally through large angles toprovide highly cambered airfoil sections for the wing, means to rotatethe opposite ailerons differentially to either side of said highlycambered position, each said wing having a lower surface slot, powerdriven blower means within the aircraft having a discharge incommunication with said lower slots to cause an outward flowtherethrough, and means to control the discharge slot flowsdifferentially in coordination with the rotation of the ailerons so thatthe slot at the down aileron receives the greater flow of air to producea jet reaction rolling force.

5. In combination in an aircraft, wings on opposite sides of theaircraft, means for modifying the wing contour of opposite wings todevelop rolling control of the aircraft over a predetermined rangethrough selective change of lift of said opposite wings, each said winghaving a discharge slot in its lower surface leading from the winginterior, said slots in a modified contour of the wing openingdownwardly and developing a substantial jet reaction component in thedirection normal to the forward portion of said wing, a blower withinthe aircraft in communication with said slots to discharge a fiowoutward and downward relative to the forward portion of said wing todevelop said jet reaction component producing a rolling moment effectiveindependently and beyond the effective range of said modifying means,and means to control the jet volume discharged from said slotsdifferentially with respect to the slots of opposite wings to controlsaid jet reaction-produced rolling moments.

6. In combination in an aircraft, a wing main body, an aileron and alift flap, means to support said body, flap and aileron in variablerelation providing for adjustment from a raised high speed position to adepressed high lift position, said wing having an inlet slot in itsupper surface in communication with the Wing interior, a blower meanshaving its inlet in communication with said inlet slot to induce aninward flow into said wing, means to depress said flap and aileronthrough large angles to provide highly cambered airfoil sections; alower surface flap spaced from said aileron and forming therebetween adischarge slot in communication with the discharge of said blower means,and means to control the opening from said discharge slot coincidentallywith the position of said aileron providing for increase in said slotopening and the mass of the jet discharge therethrough in response to alowered position of said aileron.

7. In combination in an aircraft, a Wing main body, an aileron and alift flap, means to support said body, flap and aileron in variablerelation providing for adjustment from a raised high speed position to adepressed high lift position, said wing having an inlet slot in itsupper surface in communication with the wing interior, a blower meanshaving its inlet in communication with said inlet slot to induce aninward flow into said wing, means to depress said flap and aileronthrough large angles to provide highly cambered airfoil sections, alower surface flap spaced from said aileron and forming therebetween adischarge slot in communication with the discharge of said blower means,and means for rapidly increasing the opening of said discharge slot toprovide for increased jet reaction from the mass of air dischargedtherefrom as the aileron is moved substantially into its depressedposition.

8. In combination in an aircraft, wings on opposite sides of theaircraft each having a wing main body, a lift flap and an aileron, meansfor adjustably supporting said lift flap and aileron from said wing mainbody, each said wing having an inlet slot in its upper surface incommunication with the wing interior, power driven blower means withinthe aircraft having an inlet in communication with said inlet slot toinduce an inward flow into said wing, means to depress the lift flaps onopposite wings coincidentally through large angles to provide highlycambered airfoil sections for the wings adapted to deflect the relativewind through angles up to substantially means to rotate oppositeailerons differentially to either side of said highly cambered position,each said wing having a lower surface slot in communication with thedischarge of said blower, and means to control the discharge slot flowsdifferentially in coordination with the rotation of the ailerons so thatthe slot at the down aileron receives the greater flow of air to producea jet reaction rolling force.

9. In combination, a wing main body, a flap supported in variablerelation thereto to form a wing, means forming an induction slot in saidwing, means forming a discharge slot in said wing in spaced relation tosaid induction slot, a blower in said wing, inlet duct means spaced fromthe leading edge of said wing establishing communication between saidinduction slot and the inlet side of said blower, and additional ductmeans extending along the span of said wing forwardly of said inlet ductmeans and having a rearwardly eXtending part laterally spaced from saidinlet duct means and establishing communication between the discharge ofsaid blower and said discharge slot.

10. In combination, a wing main body, a flap supported in variablerelation thereto to form a wing, means forming an induction slot in saidwing extending spanwise thereof, means forming a discharge slot in saidwing extending spanwise and located in the laterally outward portion ofthe wing span, a blower, inlet means spaced from the leading edge ofsaid wing establishing communication between said induction slot and theinlet side of said blower, and additional duct means extending along thespan of said wing forwardly of said inlet duct means and having arearwardly extending part laterally spaced from said inlet duct meansand located outwardly of said wing for establishing communicationbetween the discharge of said blower and said discharge slot.

EDWARD A. STALKER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,775,757 Gay Sept. 16, 19301,782,072 McKinstry Nov. 18, 1930 1,904,134 Hall-Brown Apr. 18, 19331,993,419 Stalker Mar. 5, 1935 2,049,573 Stalker Aug. 4, 1936 2,223,744Stalker Dec. 3, 1940 2,272,664 Gropler Feb. 10, 1942 2,277,173 Wagner etal Mar. 24, 1942 2,282,516 Gropler et a1 May 12, 1942 2,406,919 StalkerSept. 3, 1946 2,406,923 Stalker Sept. 3, 1946 FOREIGN PATENTS NumberCountry Date 870,648 France Dec. 22, 1941 i/I/I/ Certificate ofCorrection Patent No. 2,476,001 July 12, 1949 EDWARD A. STALKER It ishereby certified that error appears in the printed specification of theabove numbered patent requiring correction as follows:

Column 3, line 42, after the letter A insert down;

and that the said Letters Patent should be read with this correctiontherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 13th day of December, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

